1. Field of Invention
The present invention relates to a pressure gauge and, more particularly, to a piping and pressure-measuring apparatus for use with pumps.
2. Related Prior Art
As taught in Taiwanese Patent Publication No. 391519 issued to the present inventor, a pressure gauge includes a head 10, a handle 20 and a mouth 30. On the head 10 is installed a display 11 for showing the value of the pressure in a tire connected with the pressure gauge. In the mouth 30 is installed a wheel 40. On the mouth 30 is installed a switch 41 connected with the wheel 40. Through operating the switch 41, the mouth 30 is turned between a mode for receiving an American valve AV and another mode for receiving a French valve FV. This pressure gauge can be switched between two modes for connection with two different valves. However, it can only be used to measure the pressure in the tire. To pump the tire, the pressure gauge is removed from the valve of the tire before an air compressor or pump is connected with the valve of the tire. The pressure gauge and the air compressor or pump must be connected with and removed from the valve alternately several times before a desired value of the pressure is reached in the tire. This operation troubles a user and takes a lot of time.
Referring to FIG. 12, a pumping joint 90 is provided between an air compressor for cars and the valve of a tire of a car. The pumping joint 90 includes a gun 91. The gun 91 is connected with the air compressor at an end and connected with a pressure gauge 93 at another end. The pressure gauge 93 is further connected with a flexible pipe 92. The flexible pipe 92 is connected with a nozzle 94. The nozzle 94 can be connected with the valve. However, the pumping joint 90 can only be connected with an air compressor and cannot be connected with a pump. Moreover, the pressure gauge 93 does not work alone. The adaptability of the pumping joint 90 is limited. A user cannot carry the pumping joint 90 with him or her.
The present invention is intended to obviate or at least alleviate the problems encountered in the prior art.